Semiconductor device and method of manufacturing the same

ABSTRACT

A semiconductor device includes: a first member including a selection transistor on a front surface side of a first substrate; and a second member including a resistance change device and a connection layer that comes in contact with the resistance change device, the connection layer being bonded to a back surface of the first member.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of Japanese Priority PatentApplication JP 2013-108448 filed May 22, 2013, the entire contents ofwhich are incorporated herein by reference.

BACKGROUND

The present disclosure relates to a semiconductor device that includes aresistance change device and a selection transistor and a method ofmanufacturing the same.

As a nonvolatile memory in which information is not lost even when apower source thereof is turned off, an MRAM (Magnetoresistive RandomAccess Memory) (a magneto-resistive memory), a ReRAM (Resistive RandomAccess Memory) (a resistance change type memory), and so forth are wellknown. In addition, a memory device in which a memory layer formed bylaminating an ion source layer and a resistance change layer is includedbetween two electrodes and information is written by utilizing a change(a change in resistance) in electrical characteristics of the resistancechange layer is also proposed. All of these memory devices are adaptedto store information through a change in resistance state and will begenerally referred to as a “resistance change device” in the presentspecification.

In general, after a selection transistor and a multilayer wiring areformed on a silicon (Si) substrate, the resistance changing device isformed on its upper layer. However, nowadays, it is being attempted toarrange the resistance change device on a back surface side of thesubstrate. For example, Japanese Unexamined Patent ApplicationPublication No. 2010-171166 (see FIG. 6. FIG. 7, and so forth) describesa configuration in which a transistor is formed on a front surface sideof a substrate and a resistance change device is arranged on a backsurface side of the same substrate.

SUMMARY

It has been desired to improve the characteristics of the resistancechange device also when the resistance change device is arranged on theback surface side of the substrate in such a way.

It is desirable to provide a semiconductor device that makes it possibleto improve the characteristics of a resistance change device and amethod of manufacturing the same.

According to an embodiment of the present disclosure, there is provideda semiconductor device including: a first member including a selectiontransistor on a front surface side of a first substrate; and a secondmember including a resistance change device and a connection layer thatcomes in contact with the resistance change device, the connection layerbeing bonded to a back surface of the first member.

In the semiconductor device according to the embodiment of the presentdisclosure, since the resistance change device and the connection layerare provided in the second member that is different from the firstmember having the selection transistor, the resistance change device isformed on a surface that has no level difference caused by a lower layerstructure and is high in smoothness and therefore the characteristics ofthe resistance change device are improved.

According to an embodiment of the present disclosure, there is provideda method of manufacturing a semiconductor device. The method includes:forming a second member that includes a resistance change device and aconnection layer that comes in contact with the resistance changedevice; and bonding the connection layer to a back surface of a firstmember that includes a selection transistor on a front surface side of afirst substrate.

According to the semiconductor device according to the embodiment of thepresent disclosure or the method of manufacturing the semiconductordevice according to the embodiment of the present disclosure, since theresistance change device and the connection layer are provided in thesecond member that is different from the first member having theselection transistor and the connection layer is bonded to the backsurface of the first member, it is possible to improve thecharacteristics of the resistance change device.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary, and are intended toprovide further explanation of the technology as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of this specification. The drawings illustrate embodiments and,together with the specification, serve to explain the principles of thetechnology.

FIG. 1 is a diagram schematically illustrating a configuration of onememory cell in a semiconductor device according to a first embodiment ofthe present disclosure.

FIG. 2 is a circuit diagram illustrating a general configuration of thesemiconductor device according to the first embodiment of the presentdisclosure.

FIG. 3 is a diagram for explaining a relation between a device size of aresistance change device illustrated in FIG. 1 and a write current.

FIG. 4 is a plan view illustrating a configuration of a current magneticfield write type resistance change device.

FIG. 5 is a plan view illustrating a configuration of a spin injectionmagnetization reversal type resistance change device.

FIG. 6 is a sectional diagram illustrating the configuration of thesemiconductor device illustrated in FIG. 1 and FIG. 2.

FIG. 7 is a sectional diagram illustrating a configuration of asemiconductor device of a reference example 1 in which the resistancechange device is formed on an upper part of a multilayer wiring.

FIG. 8 is a diagram illustrating an example of a connectionconfiguration between the resistance change device and a selectiontransistor.

FIG. 9 is a diagram illustrating another example of the connectionconfiguration between the resistance change device and the selectiontransistor.

FIG. 10 is a sectional diagram illustrating a method of manufacturingthe semiconductor device illustrated in FIG. 6 in order of processes.

FIG. 11 is a sectional diagram illustrating a process following theprocesses in FIG. 10.

FIG. 12 is a sectional diagram illustrating a process following theprocess in FIG. 11.

FIG. 13 is a sectional diagram illustrating a process following theprocess in FIG. 12.

FIG. 14 is a sectional diagram illustrating a configuration of asemiconductor device according to a second embodiment of the presentdisclosure.

FIG. 15 is a sectional diagram illustrating a method of manufacturingthe semiconductor device illustrated in FIG. 14 in order of processes.

FIG. 16 is a sectional diagram illustrating a process following theprocesses in FIG. 15.

FIG. 17 is a sectional diagram illustrating a process following theprocess in FIG. 16.

FIG. 18 is a sectional diagram illustrating a process following theprocess in FIG. 17.

FIG. 19 is a top plan view illustrating the process illustrated in FIG.18.

FIG. 20 is a sectional diagram illustrating a process following theprocess in FIG. 18.

FIG. 21 is a sectional diagram illustrating a process following theprocess in FIG. 20.

FIG. 22 is a sectional diagram illustrating a configuration of asemiconductor device according to a third embodiment of the presentdisclosure.

FIG. 23 is a sectional diagram illustrating a method of manufacturingthe semiconductor device illustrated in FIG. 22 in order of processes.

FIG. 24 is a sectional diagram illustrating a process following theprocesses in FIG. 23.

FIG. 25 is a sectional diagram illustrating a process following theprocess in FIG. 24.

FIG. 26 is a sectional diagram illustrating a process following theprocess in FIG. 25.

FIG. 27 is a sectional diagram illustrating a configuration of asemiconductor device according to a fourth embodiment of the presentdisclosure.

FIG. 28 is a sectional diagram illustrating a configuration of asemiconductor device according to a fifth embodiment of the presentdisclosure.

FIG. 29 is a plan view illustrating a configuration of a perpendicularmagnetization type resistance change device illustrated in FIG. 28.

FIG. 30 is a plan view illustrating a configuration of an in-planemagnetization type resistance change device illustrated in FIG. 6.

FIG. 31 is a sectional diagram illustrating a method of manufacturingthe semiconductor device illustrated in FIG. 28 in order of processes.

FIG. 32 is a sectional diagram illustrating a process following theprocesses in FIG. 31.

FIG. 33 is a sectional diagram illustrating a process following theprocesses in FIG. 32.

FIG. 34 is a sectional diagram illustrating a process following theprocess in FIG. 33.

FIG. 35 is a sectional diagram illustrating a process following theprocess in FIG. 34.

FIG. 36 is a sectional diagram illustrating a process following theprocess in FIG. 35.

FIG. 37 is a top plan view illustrating the process illustrated in FIG.36.

FIG. 38 is a sectional diagram illustrating a process following theprocess in FIG. 36.

FIG. 39 is a sectional diagram illustrating a process following theprocess in FIG. 37.

FIG. 40 is a sectional diagram illustrating a configuration of asemiconductor device according to a sixth embodiment of the presentdisclosure.

FIG. 41 is a sectional diagram illustrating a method of manufacturingthe semiconductor device illustrated in FIG. 40 in order of processes.

FIG. 42 is a sectional diagram illustrating a process following theprocesses in FIG. 41.

FIG. 43 is a sectional diagram illustrating a process following theprocess in FIG. 42.

FIG. 44 is a sectional diagram illustrating a process following theprocess in FIG. 43.

FIG. 45 is a sectional diagram illustrating a process following theprocess in FIG. 44.

FIG. 46 is a top plan view illustrating the process illustrated in FIG.45.

FIG. 47 is a sectional diagram illustrating a process following theprocess in FIG. 46.

FIG. 48 is a sectional diagram illustrating a process following theprocess in FIG. 47.

FIG. 49 is a sectional diagram illustrating a semiconductor deviceaccording to a seventh embodiment of the present disclosure.

FIG. 50 is a sectional diagram illustrating a semiconductor deviceaccording to an eighth embodiment of the present disclosure.

FIG. 51 is a sectional diagram illustrating a configuration of asemiconductor device according to a modification example 1.

FIG. 52 is a sectional diagram illustrating a configuration of asemiconductor device according to a modification example 2.

DETAILED DESCRIPTION

In the following, embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings. It isto be noted that description will be made in the following order.

1. First Embodiment (a semiconductor device: an example of an in-planemagnetization type STT-MTJ)2. Second Embodiment (a semiconductor device: an example of the in-planemagnetization type STT-MTJ in which a common laminated section is usedas a bit line without processing a tunnel barrier layer)3. Third Embodiment (a semiconductor device: an example of the in-planemagnetization type STT-MTJ in which a bit line is provided separatelyfrom the common laminated section)4. Fourth Embodiment (a semiconductor device: an example in which amemory device section and a logic device section are laminated)5. Fifth Embodiment (a semiconductor device: an example of aperpendicular magnetization type STT-MTJ)6. Sixth Embodiment (a semiconductor device: an example of theperpendicular magnetization type STT-MTJ in which a side wall is formedon a side surface of a discrete laminated section and a bit line isprovided separately from a common laminated section)7. Seventh Embodiment (a semiconductor device: an example of a ReRAM)8. Eighth Embodiment (a semiconductor device: an example that includes amemory layer formed by laminating an ion source layer and a resistancechange layer)9. Modification Example 1 (a semiconductor device: an example in which adegree of integration is increased by providing a resistance changedevice also in a first member)10. Modification Example 2 (a semiconductor device: an example in whichthe memory device section and the logic device section are disposed on afront and a back of one substrate)

First Embodiment

FIG. 1 and FIG. 2 are diagrams each illustrating a configuration of asemiconductor device 1 according to a first embodiment of the presentdisclosure. The semiconductor device 1 is of a type in which a pluralityof memory cells 10 illustrated in FIG. 1 are arranged in a matrix asillustrated in FIG. 2 to configure a memory cell array (a memorydevice).

The memory cell 10 includes one resistance change device 20 and oneselection transistor 30 as illustrated in FIG. 1.

It is preferable that the resistance change device 20 be a spininjection magnetization reversal type memory device (STT-MTJ: SpinTransfer Torque-Magnetic Tunnel Junctions) that may include, forexample, a record layer 21, a tunnel barrier layer 22, and a referencelayer 23.

In a typical structural example of the in-plane magnetization typedevice, the reference layer 23 has a laminated structure configured ofan antiferromagnetic material made of PtMn, IrMn, and so forth, and asingle layer of CoFe, CoFeB, and so forth or a laminated ferri-structureof CoFe/Ru/CoFeB and so forth. The tunnel barrier layer 22 may beconfigured of an oxide film made of, for example, AlO, MgO, and soforth. The record layer 21 may be configured of, for example, a singlelayer of CoFe, CoFeB, NiFe, and so forth or a laminated structure inwhich a layer of Ru, MgO, and so forth is sandwiched between layers ofCoFe, CoFeB, NiFe, and so forth.

FIG. 3 to FIG. 5 are diagrams adapted to explain the reason why it ispreferable to configure the resistance change device 20 by the STT-MTJ.Examples of the MTJ device include a current magnetic field write type(MRAM) device in which a magnetic field is generated by making a currentflow between a selected bit line BL and a selected word line WL and aspin injection magnetization reversal type (STT-MTJ) device in whichinformation writing is performed by utilizing spin injectionmagnetization reversal with a current. In the current magnetic fieldwrite type device, the current for magnetization reversal is increasedwith miniaturization of the MTJ device and power consumption isincreased accordingly as illustrated in FIG. 3. In addition, since writeword lines WWL are included as illustrated in FIG. 4, the cell area isincreased. Further, the probability that information may be erroneouslywritten into an adjacent MTJ device due to the magnetic field generatedat the time of writing is high.

On the other hand, in the spin injection magnetization reversal typedevice, the current desired for magnetization reversal is decreased withminiaturization of the MTJ device and hence power consumption saving ispromoted as illustrated in FIG. 3. In addition, since the write wordlines WWL are unnecessary, the cell area is decreased as illustrated inFIG. 5. Therefore, it becomes possible to cope with high integration andminiaturization.

In addition, it is preferable that the record layer 21 be connected to adrain of the selection transistor 30 and the reference layer 23 beconnected to the bit line BL as illustrated in FIG. 1. The reasontherefor will be described later.

The selection transistor 30 illustrated in FIG. 1 may be, for example,an N type MOS transistor, and the drain thereof is connected to therecord layer 21 of the resistance change device 20, a gate thereof isconnected to a word line WL, and a source thereof is connected to asource line SL. In addition, the sources of two selection transistors 30that are adjacent to each other in an extending direction of the bitline BL are connected to the same source line SL. The bit line BL andthe source line SL are connected to a bipolar write pulse/read biasgenerator 11. The bit line BL is connected to one of terminals of asense amplifier 12. The other terminal of the sense amplifier 12 isconnected to a voltage reference circuit 13.

The semiconductor device 1 includes the plurality of memory cells 10that are arranged in a matrix, the plurality of word lines WL extendingin a row direction (a lateral direction), and the plurality of bit linesBL and the plurality of source lines SL each extending in a columndirection (a longitudinal direction) as illustrated in FIG. 2. Eachmemory cell 10 is connected to the word line WL, the bit line BL, andthe source line SL.

FIG. 6 illustrates a sectional configuration of the semiconductor device1 so configured. In the following description, Z indicates a laminationdirection and an XY plane indicates a plane orthogonal to the laminationdirection.

The semiconductor device 1 is divided into a memory device section 1Aand a logic device section 1B in an in-plane direction of the XY plane.The memory device section 1A and the logic device section 1B may beseparated from each other, for example, by a device separation layer 1Chaving an STI (Shallow Trench Isolation) structure.

In the memory device section 1A, the memory cells 10 each including theresistance change device 20 and the selection transistor 30 illustratedin FIG. 1 and FIG. 2 are arranged. The two memory cells 10 that aremutually adjacent in the extending direction of the bit line BL and arenot connected to the same source line SL may be separated from eachother by, for example, a device separation layer 1D having the STIstructure.

The logic device section 1B includes a transistor 40 of a peripheralcircuit and a multilayer wiring 50.

On the other hand, the semiconductor device 1 has a configuration inwhich a first member 60 and a second member 70 are bonded together alonga bonding surface 81 when viewed in the lamination direction Z. Thefirst member 60 includes a first substrate 61, and the selectiontransistor 30 and the transistor 40 of the peripheral circuit aredisposed on a front surface 61A side of the first substrate 61. Thesecond member 70 includes the resistance change device 20 and aconnection layer 71 that is in contact with the resistance change device20, and the connection layer 71 is bonded to a back surface 60B of thefirst member 60. Accordingly, in the semiconductor device 1, it ispossible to improve the characteristics of the resistance change device20.

Specifically, the resistance change device 20 is provided in the secondmember 70 that is different from the first member 60 having theselection transistor 30, which makes it possible to form the resistancechange device 20 on the surface that has no level difference caused bylower layer structures and is high in smoothness, and accordingly itbecomes possible to improve the characteristics of the resistance changedevice 20.

The first member 60 may include, for example, the first substrate 61,the selection transistor 30, the transistor 40 of the peripheralcircuit, an interlayer insulating film 62, a front surface contactelectrode 63, the source line SL, the multilayer wiring 50, and a backsurface contact electrode 64.

The first substrate 61 may have a configuration in which, for example, asemiconductor region (not illustrated) is disposed on an insulating film(not illustrated). The insulating film may be configured of, forexample, a silicon nitride (SiN) film, a silicon oxide (SiO₂) film, asilicon oxycarbide (SiOC) film, a silicon oxycarbide nitride (SiOCN)film, or a composite film of these films. In addition, the insulatingfilm may be configured of an insulating film made of the material thatis used as an interlayer insulating film of the general semiconductordevice such as an organic insulating film. The semiconductor region maybe configured of, for example, a silicon (Si) layer. It is to be notedthat each of the above-mentioned device separation layers 1C and 1Dhaving the STI structure is formed by embedding a silicon oxide filminto a device separation groove provided in the semiconductor region.

The selection transistor 30 includes a gate electrode 31 on the frontsurface 61A of the first substrate 61 with a gate insulating film (notillustrated) in between. Diffusion layers (not illustrated) to be servedas source-drain regions are provided in the semiconductor region of thefirst substrate 61 on both sides of the gate electrode 31. Thesemiconductor region between these two diffusion layers serves as achannel region of the selection transistor 30.

In addition, low resistance sections 32A and 32B are disposed on frontsurfaces of the respective diffusion layers. The low resistance section32A is shared by the two selection transistors 30 that are mutuallyadjacent in the extending direction of the bit line BL and is connectedto the source line SL via the front surface contact electrode 63. Thelow resistance section 32B is separately provided for each selectiontransistor 30. The low resistance section 32B is connected to theconnection layer 71 and the resistance change device 20 via the backsurface contact electrode 64 formed through the first substrate 61. Theresistance change device 20 and the selection transistor 30 areconnected to each other by the shallow back surface contact electrode 64in this way, which makes it possible to reduce connection resistance, toimprove MOSFET performance, and to improve yield of the back surfacecontact electrode 64.

The materials of the gate insulating film, the gate electrode 31, thelow resistance sections 32A and 32B, and so forth are the same as thematerials of the gate insulating film, the gate electrode, and the lowresistance sections of the general semiconductor device.

The transistor 40 of the peripheral circuit is disposed on the frontsurface 61A side of the first substrate 61 in the first member 60.Specifically, the transistor 40 of the peripheral circuit includes agate electrode 41 with a gate insulating film (not illustrated) inbetween on the front surface 61A of the first substrate 61. Diffusionlayers (not illustrated) to be served as source-drain regions areprovided in the semiconductor region of the first substrate 61 on bothsides of the gate electrode 41. The semiconductor region between thesetwo diffusion layers serves as a channel region of the transistor 40.

In addition, low resistance sections 42A and 42B are provided on frontsurfaces of the respective diffusion layers. The multilayer wiring 50 isconnected to the low resistance sections 42A and 42B. The multilayerwiring 50 is formed by laminating a plurality of layers (for example,about three layers in the example in FIG. 6) of contact electrodes andwirings.

The materials of the gate insulating film, the gate electrode 41, thelow resistance sections 42A and 42B, and so forth are the same as thematerials of the gate insulating film, the gate electrode, and the lowresistance sections of the general semiconductor device.

The interlayer insulating film 62 may have a thickness of, for example,several hundred nm or more and the front surface thereof is flattened. Asupport substrate (not illustrated) may be provided on the interlayerinsulating film 62.

The second member 70 includes the resistance change device 20, theconnection layer 71, and the bit line BL (or a power source line). Theresistance change device 20, the connection layer 71, and the bit lineBL are embedded in the substrate or a protection film (an interlayerinsulating film) 72.

The resistance change device 20 is a spin injection magnetizationreversal type memory device that includes a cap layer 24, the recordlayer 21, the tunnel barrier layer 22, the reference layer 23, anantiferromagnetic layer 25, and a buffer layer 26 in this order startingfrom a side close to the connection layer 71 as illustrated with anenlarged size in FIG. 6. In other words, the resistance change device 20has a bottom pin structure that includes the reference layer 23, thetunnel barrier layer 22, and the record layer 21 in this order frombottom to top in the lamination direction Z, and the record layer 21 isconnected to the drain of the selection transistor 30.

The above-mentioned matter will be described with reference to FIG. 7 toFIG. 9. The MTJ is formed at a low temperature in order to minimize thedamage by heat history to the magnetic material. Although it isdesirable to lower the process temperature throughout the manufacturingprocess when regarding characteristics such as TMR (tunnelmagnetoresistance) and so forth as important, the reliability of thetransistors 30 and 40 and the wiring may be probably reduced when theprocess temperature has been lowered. In addition, in a nonvolatilelogic and a magnetic memory, the peripheral circuit that includes thesense amplifier 12, the driving transistor 40, and so forth has amultilayer wiring structure of about four or more layers. Therefore,from the viewpoint of heat resistance and reliability, the resistancechange device 20 configured of the MTJ is formed on an upper part of themultilayer wiring 50 in many cases as illustrated in FIG. 7. In thiscase, wiring resistance and parasitic capacitance may be increased and ahigh-speed operation may probably become difficult.

In addition, the upper part of the multilayer wiring 50 has many leveldifferences caused by the lower layer structures such as the contactelectrode and the wiring and thus is low in smoothness. Therefore, ifthe MTJ having a top pin structure that includes the record layer 21,the tunnel barrier layer 22, and the reference layer 23 in this orderfrom bottom to top in the lamination direction Z is formed on the upperpart of the multilayer wiring 50, the characteristics of theantiferromagnetic material (InMn is mainly used) may be degraded and theTMR may be reduced. Therefore, when the MTJ is formed on the upper partof the multilayer wiring 50, it is general to adopt the bottom pinstructure that includes the reference layer 23, the tunnel barrier layer22, and the record layer 21 in this order from bottom to top in thelamination direction Z as illustrated in FIG. 8.

It is to be noted that it is also possible to form the MTJ having thebottom pin structure on the upper part of the multilayer wiring 50 andto connect the record layer 21 to the drain of the selection transistor30 by routing of wiring as illustrated in FIG. 9. However, aconfiguration for routing of wiring is complicated and the cell area isincreased in the above-mentioned case.

On the other hand, the first embodiment is configured such that thesecond member 70 having the resistance change device 20 is bonded to theback surface 60B of the first member 60 that includes the selectiontransistor 30 as illustrated in FIG. 6. Accordingly, it becomes possibleto form the resistance change device 20 on the surface that has no leveldifference caused by the lower layer structures and is high insmoothness and thus it becomes possible to improve the characteristicsof the resistance change device 20. In addition, increases in wiringresistance and parasitic capacitance illustrated in FIG. 7 are alsoeliminated and the high-speed operation becomes possible. Further, itbecomes possible to apply a fine design rule by arranging the resistancechange device 20 on the back surface 60B side of the first member 60 andthus formation of a memory of large capacity is facilitated.

In addition, in the first embodiment, it becomes possible to connect therecord layer 21 to the drain of the selection transistor 30 by adoptingsuch a bonding configuration, without performing complicated routing ofwiring illustrated in FIG. 9 while maintaining the bottom pin structure.In other words, the characteristics of the antiferromagnetic materialmade of PtMn are improved and the characteristics such as the TMR areincreased by adopting the bottom pin structure. Further, it becomespossible to drive the selection transistor 30 with a small current andasymmetry of the write current is moderated (a deviation in switchingvoltage is reduced) by connecting the record layer 21 to the drain ofthe selection transistor 30.

The materials of the respective layers of the resistance change device20 illustrated in FIG. 6 will be described. In a typical structuralexample of the in-plane magnetization type device, the antiferromagneticlayer 25 is configured of the antiferromagnetic material made of PtMn,IrMn, and so forth. The reference layer 23 has the laminated structureconfigured of the antiferromagnetic material made of PtMn, IrMn, and soforth, and the single layer of CoFe, CoFeB, and so forth or thelaminated ferri-structure of CoFe/Ru/CoFeB and so forth. The tunnelbarrier layer 22 may be configured of an oxide film made of, forexample, AlO, MgO, and so forth. The record layer 21 may be configuredof, for example, the single layer of CoFe, CoFeB, NiFe, and so forth orthe laminated structure in which the layer of Ru, MgO, or the like issandwiched between the layers of CoFe, CoFeB, NiFe, and so forth.

The buffer layer 26 may be configured of, for example, a single layer ora laminated film of copper (Cu), ruthenium (Ru), tantalum (Ta), titanium(Ti), tungsten (W), TiN, and so forth. The materials of the cap layer 24are same as those of the buffer layer 26.

The connection layer 71 and the bit line BL illustrated in FIG. 6 havefunctions of serving as two electrodes of the resistance change device20. The connection layer 71 is separated into parts for each of theplurality of resistance change devices 20. On the other hand, the bitline BL is provided as a wiring that is common to the plurality ofresistance change devices 20. Each of the connection layer 71 and thebit line BL may be configured of the single layer or the laminated filmof, for example, copper (Cu), ruthenium (Ru), tantalum (Ta), titanium(Ti), tungsten (W), TiN, and so forth.

Further, the diffusion layer of the selection transistor 30 of thememory device section 1A and the diffusion layer of the transistor 40 ofthe logic device section 1B are connected together via as connectionsection 1E. The connection section 1E may be disposed between the lowresistance section 42A of the transistor 40 of the peripheral circuitand the bit line BL extended in the logic device section 1B, and has aconfiguration in which the back surface contact electrode 64, theconnection layer 71, and the resistance change device 20 are laminatedin this order. This makes it possible to form the connection section 1Ein the same process as that of the back surface contact electrode 64,the connection layer 71, and the resistance change device 20, and makesit possible to simplify the configuration and the manufacturing processof the connection section 1E. It is to be noted that it is preferablethat the resistance change device 20 to be connected to the connectionsection 1E be larger in area than the resistance change device 20 (theresistance change device 20 that operates as a memory device) in thememory cell 10 for resistance reduction of the connection section 1E.Information writing into the resistance change device 20 to be connectedto the connection section 1E does not occur with a current with whichwriting into the resistance change device 20 operating as the memorydevice is performed by making the area of the resistance change device20 to be connected to the connection section 1E larger than the area ofthe resistance change device 20 operating as the memory device.

The semiconductor device 1 may be manufactured, for example, in thefollowing manner.

FIG. 10 to FIG. 13 are diagrams illustrating a method of manufacturingthe semiconductor device 1 in order of processes. First, as illustratedin FIG. 10, the selection transistor 30, the transistor 40 of theperipheral circuit, the interlayer insulating film 62, the front surfacecontact electrode 63, the source line SL, and the multilayer wiring 50are formed on the front surface 61A side of the first substrate 61. Inaddition, the first substrate 61 is turned over and the back surfacecontact electrode 64 is formed on the back surface 61B of the firstsubstrate 61. The back surface contact electrode 64 reaches the lowresistance section 32B of the selection transistor 30 or the lowresistance section 42A of the transistor 40 of the peripheral circuit.Thus, the first member 60 is formed.

Then, as illustrated in FIG. 11, a resistance change device materialfilm 29 and a connection layer material film 71A are formed on a secondsubstrate 73. As the second substrate 73, a monocrystalline substratesuch as a Si substrate, a GaAs substrate, and an MgO substrate may bepreferable from the viewpoint of smoothness and magneticcharacteristics. As a film deposition method, a sputtering method, avapor deposition method, a CVD (Chemical Vapor Deposition) method, andso forth may be used. As the resistance change material film 29, abuffer layer material film 26A, an antiferromagnetic layer material film25A, a reference layer material film 23A, a tunnel barrier layermaterial film 22A, a record layer material film 21A, and a cap layermaterial film 24A are formed in this order starting from a side close tothe second substrate 73 as illustrated with an enlarged size in FIG. 11.

Then, the second substrate 73 on which the resistance change devicematerial film 29 and the connection layer material film 71A are formedmay be bonded to the back surface 60B of the first member 60 by using asubstrate bonding technique such as, for example, normal temperaturebonding and the second substrate 73 is removed by etching and so forthas illustrated in FIG. 12. Here, the second substrate 73 on which theresistance change device material film 29 and the connection layermaterial film 71A are formed may be bonded to the entire back surface60B of the first member 60 or may be partially bonded only to a portionwhere the resistance change device 20 is to be formed.

Thereafter, the resistance change device material film 29 and theconnection layer material film 71A are patterned into desired shapes byRIE (Reactive Ion Etching), ion milling, or the like, to form theresistance change device 20 and the connection layer 71 as illustratedin FIG. 13. The connection layer 71 is bonded to the back surface 60B ofthe first member 60.

Here, the plane of the resistance change device 20 has an elliptic shapeor a shape similar to the elliptic shape so as to attain an aspect ratioof about 1.5 to about 2.5 both inclusive in the case of the in-planemagnetization type device as illustrated in FIG. 5. Further, it ispreferable that the aspect ratio be about 2 or more from the viewpointof improvement in record holding characteristics.

Further, the protection film 72 is formed so as to embed the resistancechange device 20 and the connection layer 71 and the bit line BL isformed. The bit line BL may be formed mainly using a material such as Cuby, for example, a dual damascene method and so forth. Further, the bitline BL is embedded with the protection film 72. As a result of theabove, formation of the semiconductor device 1 illustrated in FIG. 6 iscompleted.

In this semiconductor device 1, a current is applied in a film surfacevertical direction of the resistance change device 20 according towhether potentials of the source line SL and the bit line BL are high orlow and spin torque magnetization reversal occurs. Thus, the resistanceof the resistance change device 20 is changed to a high or low value bydirecting the magnetization of the record layer 21 parallel with orantiparallel to the magnetization of the reference layer 23, therebyexecuting information writing.

On the other hand, in order to read out information stored in theresistance change device 20, a magnetic layer (not illustrated) to serveas a reference of the information is disposed on the resistance changedevice 20 with a thin insulating film in between, thereby reading outthe information with a ferromagnetic tunnel current flowing through thetunnel barrier layer 22.

Here, since the resistance change device 20 and the connection layer 71are provided in the second member 70 that is different from the firstmember 60 including the selection transistor 30, the resistance changedevice 20 is formed on the surface that has no level difference causedby the lower layer structures and is high in smoothness and thereforethe characteristics of the resistance change device 20 are improved. Inaddition, the increases in wiring resistance and parasitic capacitanceillustrated in FIG. 7 are eliminated and the high-sped operation becomespossible.

In addition, the resistance change device 20 has the bottom pinstructure that includes the reference layer 23, the tunnel barrier layer22, and the record layer 21 in this order from bottom to top in thelamination direction Z, and the record layer 21 is connected to thedrain of the selection transistor 30. Therefore, the characteristics ofthe antiferromagnetic material made of PtMn are improved and thecharacteristics such as the TMR are increased by adopting the bottom pinstructure. In addition, the selection transistor 30 is driven with asmall current and the asymmetry of the write current is mitigated (thedeviation of switching voltage is reduced) by connecting the recordlayer 21 to the drain of the selection transistor 30.

Since, in the first embodiment, the resistance change device 20 and theconnection layer 71 are disposed in the second member 70 that isdifferent from the first member 60 including the selection transistor 30as described above, the resistance change device 20 is allowed to beformed on the surface that has no level difference caused by the lowerlayer structures and is high in smoothness and therefore it becomespossible to improve the characteristics of the resistance change device20. In addition, the increases in wiring resistance and parasiticcapacitance illustrated in FIG. 7 are eliminated and the high-speedoperation becomes possible. Further, it becomes possible to apply thefine design rule by arranging the resistance change device 20 on theback surface 60B of the first member 60, thereby facilitating formationof the memory of large capacity.

In addition, the resistance change device 20 has the bottom pinstructure that includes the reference layer 23, the tunnel barrier layer22, and the record layer 21 in this order from bottom to top in thelamination direction Z, and the record layer 21 is connected to thedrain of the selection transistor 30. Therefore, the characteristics ofthe antiferromagnetic material made of PtMn are improved and thecharacteristics such as the TMR are increased by adopting the bottom pinstructure. In addition, it becomes possible to drive the selectiontransistor 30 with the small current and the asymmetry of the writecurrent is mitigated (the deviation of switching voltage is reduced) byconnecting the record layer 21 to the drain of the selection transistor30.

Second Embodiment

FIG. 14 is a diagram illustrating an example of a sectionalconfiguration of a semiconductor device 2 according to a secondembodiment of the present disclosure. In the second embodiment,insulation and reliability of the tunnel barrier layer 22 is improved bynot processing the tunnel barrier layer 22 of the resistance changedevice 20. The semiconductor device 2 has the same configuration,function, and effects as the semiconductor device 1 according to theabove-mentioned first embodiment except for the above-mentioned point.Accordingly, description will be made by assigning the same numerals tothe corresponding constitutional elements.

The plurality of resistance change devices 20 are provided in the secondmember 70. The plurality of resistance change devices 20 include adiscrete laminated section 20A that includes the record layer 21 and isseparated into parts for each of the plurality of resistance changedevices 20 and a common laminated section 20B that includes the tunnelbarrier layer 22 and the reference layer 23 and is common to theplurality of resistance change devices 20.

It is preferable that the common lamination section 20B also serve as awiring that is common to the plurality of resistance change devices 20,specifically, the bit line BL. Simplification and cost saving of themanufacturing process become possible by omitting the process of formingthe bit line BL.

The connection layer 71 is separated into parts for each of theplurality of resistance change devices 20 together with the discretelaminated section 20A.

The semiconductor device 2 may be manufactured, for example, in thefollowing manner.

FIG. 15 to FIG. 21 are diagrams illustrating a method of manufacturingthe semiconductor device 2 in order of processes. It is to be noted thatwith respect to the processes that are the same as those in the firstembodiment, description will be made with reference to FIG. 10 to FIG.13.

First, the first member 60 is formed by the process illustrated in FIG.10 in the same way as in the first embodiment.

Then, the resistance change device material film 29 and the connectionlayer material film 71A are formed on the second substrate 73 by theprocess illustrated in FIG. 11 in the same way as in the firstembodiment. As the resistance change device material film 29, the bufferlayer material film 26A, the antiferromagnetic layer material film 25A,the reference layer material film 23A, the tunnel barrier layer materialfilm 22A, the record layer material film 21A, and the cap layer materialfilm 24A are formed in this order starting from the side close to thesecond substrate 73 as illustrated with the enlarged size in FIG. 11.

Then, a resist R1 is formed on the connection layer material film 71A asillustrated in FIG. 15.

Thereafter, the connection layer material film 71A and the resistancechange device material film 29 are patterned by the RIE, the ionmilling, or the like by using the resist R1 as the mask to form theconnection layer 71 and the plurality of resistance change devices 20.

In that case, the discrete laminated section 20A that includes the caplayer 24 and the record layer 21 and the common laminated section 20Bthat includes the tunnel barrier layer 22, the reference layer 23, theantiferromagnetic layer 25, and the buffer layer 26 are provided for theplurality of resistance change devices 20. The discrete laminatedsection 20A is separated into parts for each of the plurality of theresistance change devices 20. The connection layer 71 is formed by beingseparated into parts for each of the plurality of the resistance changedevices 20 together with the discrete laminated section 20A. The commonlaminated section 20B is continuously provided across the plurality ofthe resistance change devices 20.

The damage to the tunnel barrier layer 22 upon etching is suppressed anddegradation of insulation of the tunnel barrier layer 22 caused byre-deposition that would occur when etching the reference layer 23 andsucceeding layers is suppressed by not processing the tunnel barrierlayer 22 and processing the layers up to the record layer 21. Thus, itbecomes possible to improve the insulation and the reliability of thetunnel barrier layer 22.

As with the first embodiment, the plane of the resistance change device20 has the elliptic shape or the shape similar to the elliptic shape soas to attain the aspect ratio of about 1.5 to about 2.5 both inclusivein the case of the in-plane magnetization type device as illustrated inFIG. 5. Further, it is preferable that the aspect ratio be about 2 ormore from the viewpoint of improvement in record holding property.

Then, a resist R2 that covers the discrete laminated section 20A isformed as illustrated in FIG. 17.

Thereafter, the common laminated section 20B is patterned by the REI,the ion milling, or the like by using the resist R2 as a mask to formthe bit line BL as illustrated in FIG. 18 and FIG. 19. Thus, the commonlaminated section 20B is made to also serve as the bit line BL.

After formation of the bit line BL, the protection film (the interlayerinsulating film) 72 is formed so as to embed the connection layer 71 andthe resistance change device 20 as illustrated in FIG. 20. Then, theprotection film 72 may be polished, for example, by CMP (ChemicalMechanical Polishing) to expose the connection layer 71 as illustratedin FIG. 21. Thus, the second member 70 in which the resistance changedevice 20 and the connection layer 71 are formed on the second substrate73 is formed.

Then, the second member 70 may be bonded to the back surface 60B of thefirst member 60 by using, for example, the substrate bonding techniquesuch as normal temperature bonding and so forth. The second substrate 73may be either left or removed by etching and so forth. As a result ofthe above, formation of the semiconductor device 2 illustrated in FIG.14 is completed.

Since, in the second embodiment, the common laminated section 20B thatincludes the tunnel barrier layer 23 and the reference layer 23 of theresistance change device 20 is not processed, it becomes possible toimprove the insulation and reliability of the tunnel barrier layer 22.In addition, since the common laminated section 20B is used as the bitline BL that is common to the plurality of resistance change devices 20,both of process reduction and cost saving become possible.

Third Embodiment

FIG. 22 is a diagram illustrating a sectional configuration of asemiconductor device 3 according to a third embodiment of the presentdisclosure. In the third embodiment, the bit line BL is providedseparately from the common laminated section 20B of the resistancechange device 20. The semiconductor device 3 has the same configuration,function, and effects as the semiconductor device 2 of the secondembodiment except for the above-mentioned point. Therefore, descriptionwill be made by assigning the same numerals to the correspondingconstitutional elements.

The semiconductor device 3 may be manufactured, for example, in thefollowing manner.

FIG. 23 to FIG. 27 are diagrams illustrating a method of manufacturingthe semiconductor device 3 in order of processes. It is to be noted thatwith respect to the processes that are the same as those in the firstembodiment, description will be made with reference to FIG. 10 to FIG.13 and with respect to the processes that are the same as those in thesecond embodiment, description will be made with reference to FIG. 15 toFIG. 21.

First, the first member 60 is formed by the process illustrated in FIG.10 in the same way as in the first embodiment.

Then, after the bit line BL is formed on the second substrate 73, theresistance change device material film 29 and the connection layermaterial film 71A are formed on the entire surface on which the bit lineBL has been formed, as illustrated in FIG. 23. As the film depositionmethod, it is possible to use the sputtering method, the vapordeposition method, the CVD method, and so forth as in the case in thefirst embodiment. As the resistance change device material film 29, thebuffer layer material film 26A, the antiferromagnetic layer materialfilm 25A, the reference layer material film 23A, the tunnel barrierlayer material film 22A, the record layer material film 21A, and the caplayer material film 24A are formed in this order starting from the sideclose to the second substrate 73 as illustrated with an enlarged size inFIG. 23.

Then, the connection layer material film 71A and the resistance changedevice material film 29 are patterned by the RIE, the ion milling, orthe like, to form the connection layer 71 and the plurality ofresistance change devices 20 in the same way as in the secondembodiment, as illustrated in FIG. 24. The discrete laminated section20A that includes the record layer 21 and the cap layer 24 and thecommon laminated section 20B that includes the tunnel barrier layer 22,the reference layer 23, the antiferromagnetic layer 25, and the bufferlayer 26 are provided for the plurality of resistance change devices 20.The discrete laminated section 20A and the connection layer 71 arerespectively separated into parts for each of the plurality ofresistance change devices 20. The common laminated section 20B iscontinuously provided across the plurality of resistance change devices20.

Then, the protection film (the interlayer insulating film) 72 is formedso as to embed the connection layer 71, the resistance change device 20,and the bit line BL in the same way as in the second embodiment, asillustrated in FIG. 25. Thereafter, the protection film 72 is polishedby the CMP to expose the connection layer 71 in the same way as in thesecond embodiment, as illustrated in FIG. 26. Thus, the second member 70in which the bit line BL, the resistance change device 20, and theconnection layer 71 are formed on the second substrate 73 is formed.

Then, the second member 70 may be bonded to the back surface 60B of thefirst member 60 by using, for example, the substrate bonding techniquesuch as normal temperature bonding. The second substrate 73 may beeither left or removed by etching and so forth. As a result of theabove, formation of the semiconductor device 3 illustrated in FIG. 22 iscompleted.

Fourth Embodiment

FIG. 27 is a diagram illustrating a sectional configuration of asemiconductor device 4 according to a fourth embodiment of the presentdisclosure. In the fourth embodiment, the memory device section 1A andthe logic device section 1B are laminated in the lamination direction Zso as to further reduce the wiring resistance and to further improve thedegree of integration. The semiconductor device 4 has the sameconfiguration, function, and effects as the semiconductor device 1according to the first embodiment except for the above-mentioned point.Therefore, description will be made by assigning the same numerals tothe corresponding constitutional elements.

The memory device section 1A has the configuration in which the firstmember 60 and the second member 70 are bonded together along the bondingsurface 81 in the same way as in the first embodiment. The first member60, the second member 70, the resistance change device 20, and theselection transistor 30 are configured in the same way as in the firstto third embodiments. FIG. 27 illustrates an example of a case that thefirst member 60, the second member 70, the resistance change device 20,and the selection transistor 30 are configured in the same way as in thefirst embodiment.

The logic device section 1B is provided in a third member 90 differentfrom the first member 60 and the second member 70. A back surface 90B ofthe third member 90 is bonded to a front surface 60A of the first member60 along a bonding surface 82.

The third member 90 includes the transistor 40 of the peripheral circuiton a front surface 91A side of a third substrate 91. The adjacenttransistors 40 are separated by a device separation layer 1F. Themultilayer wiring 50 is connected to the low resistance sections 42A and42B of the transistor 40. The multilayer wiring 50 is disposed in aninterlayer insulating film 92.

Further, the diffusion layer of the selection transistor 30 of thememory device section 1A and the diffusion layer of the transistor 40 ofthe logic device section 1B are connected together via a connectionsection 1G. The connection section 1G is disposed between the lowresistance section 42A of the transistor 40 of the peripheral circuitand the bit line BL extended in the logic device section 1B. Theconnection section 1G may have a configuration in which, for example,the resistance change device 20, the connection layer 71, the backsurface contact electrode 64, a low resistance section 32C, a frontsurface contact electrode 63C, a wiring layer 65, a low resistancesection 93, a back surface contact electrode 94 are laminated in thisorder starting from a side close the bit line BL. The low resistancesection 32C is disposed on the same layer as the low resistance sections32A and 32B of the selection transistor 30. The front surface contactelectrode 63A and the wiring layer 65 are disposed on the same layer asthe front surface contact electrode 63 and the source line SL. The lowresistance section 93 is disposed on a back surface 91B of the thirdsubstrate 91. The back surface contact electrode 94 is disposed betweenthe low resistance section 42A of the transistor 40 of the peripheralcircuit and the low resistance section 93 so as to penetrate through thethird substrate 91. It is to be noted that it is also possible toconnect the back surface contact electrode 94 directly to the wiringlayer 65 by omitting the low resistance section 93. However, provisionof the low resistance section 93 makes it possible to select thematerial suitable for normal temperature bonding as the material of thelow resistance section 93 and therefore it becomes possible to improvebonding strength.

It is possible to manufacture the semiconductor device 4 in the same wayas the semiconductor device 1 of the first embodiment except that thelogic device section 1B is formed in the third member 90 different fromthe first member 60 and the second member 70 and the back surface 90B ofthe third member 90 is bonded to the front surface 60A of the firstmember 60 along the bonding surface 82.

Fifth Embodiment

FIG. 28 is a diagram illustrating a sectional configuration of asemiconductor device 5 according to a fifth embodiment of the presentdisclosure. In the fifth embodiment, a perpendicular magnetization typeSTT-MTJ is included as the resistance change device 20. The record layer21 and the reference layer 23 are each configured of a film, an axis ofeasy magnetization of which is directed in a vertical direction relativeto a film surface. The semiconductor device 5 has the sameconfiguration, function, and effects as the semiconductor device 1 ofthe above-mentioned first embodiment except for the above-mentionedpoint. Therefore, description will be made by assigning the samenumerals to the corresponding constitutional elements.

The resistance change device 20 is a spin injection magnetizationreversal type memory device that includes the cap layer 24, the recordlayer 21, the tunnel barrier layer 22, the reference layer 23, aperpendicular magnetization layer 27, and the buffer layer 26 in thisorder starting from a side close to the connection layer 71 asillustrated with the enlarged size in FIG. 28. In other words, theresistance change device 20 has the bottom pin structure that includesthe reference layer 23, the tunnel barrier layer 22, and the recordlayer 21 in this order from bottom to top in the lamination direction Z,and the record layer 21 is connected to the drain of the selectiontransistor 30.

The perpendicular magnetization layer 27 may be a perpendicularmagnetization film configured of, for example, a single layer of aCoPt-based alloy, TbFeCo, GdFeCo, FePt, or CoCrPt, a laminated layer ofCo/Pt, or a laminated layer of Fe/Pt. The reference layer 23 may beconfigured of, for example, a single layer of CoFe, CoFeB, and so forthor a laminated ferri-structure of CoFe/Ru/CoFeB and so forth. The tunnelbarrier layer 22 may be configured of, for example, an oxide film suchas AlO and MgO. The record layer 21 is configured of a single layer ofCoFe, CoFeB, and so forth, a laminated structure in which a layer of Ru,MgO, and so forth is sandwiched between layers of CoFe, CoFeB, NiFe, andso forth, or a laminated structure configured of a layer of CoFe, CoFeB,and so forth and the perpendicular magnetization film.

When the resistance change device 20 is configured of the perpendicularmagnetization type STT-MTJ, it is possible to make its shape small intoa circular shape or a shape similar to the circular shape as illustratedin FIG. 29 unlike the in-plane magnetization type device, and furtherminiaturization of the resistance change device 20 becomes possible. Itis to be noted that an example of the planar shape of the in-planemagnetization type device is illustrated in FIG. 30 for readyunderstanding.

The semiconductor device 5 may be manufactured, for example, in thefollowing manner.

FIG. 31 to FIG. 39 are diagrams illustrating a method of manufacturingthe semiconductor device 5 in order of processes. It is to be noted thatwith respect to the processes that are the same as those in the firstembodiment, description will be made with reference to FIG. 10 to FIG.13.

First, the first member 60 is formed by the process illustrated in FIG.10 in the same way as in the first embodiment, as illustrated in FIG.31.

Then, the resistance change device material film 29 and the connectionlayer material film 71A are formed on the second substrate 73 by theprocess illustrated in FIG. 11 in the same way as in the firstembodiment, as illustrated in FIG. 32. As the resistance change devicematerial film 29, the buffer layer material film 26A, a perpendicularmagnetization material film 27A, the reference layer material film 23A,the tunnel barrier layer material film 22A, the record layer materialfilm 21A, and the cap layer material film 24A are formed in this orderstarting from the side close to the second substrate 73 as illustratedwith the enlarged size in FIG. 32.

Then, the resist R1 is formed on the connection layer material film 71Aas illustrated in FIG. 33.

Thereafter, the connection layer material film 71A and the resistancechange device material film 29 are patterned by the RIE, the ionmilling, or the like by using the resist R1 as the mask to form theconnection layer 71 and the plurality of resistance change devices 20.

In that case, the discrete laminated section 20A that includes therecord layer 21 and the cap layer 24 and the common laminated section20B that includes the tunnel barrier layer 22, the reference layer 23,the perpendicular magnetization layer 27, and the buffer layer 26 areprovided for the plurality of resistance change devices 20. The discretelaminated section 20A and the connection layer 71 are respectivelyseparated into parts for each of the plurality of resistance changedevices 20. The plane of the discrete laminated section 20A is formedinto the circular shape or the shape similar to the circular shape asillustrated in FIG. 29. The common laminated section 20B is continuouslyprovided across the plurality of resistance change devices 20.

The damage to the tunnel barrier 22 upon etching is suppressed anddegradation of insulation of the tunnel barrier layer 22 caused byre-deposition that would occur when etching the reference layer 23 andsucceeding layers is suppressed by not processing the tunnel barrierlayer 22 and processing the layers up to the record layer 21.Accordingly, it becomes possible to improve the insulation andreliability of the tunnel barrier layer 22.

Then, the resist R2 that covers the discrete laminated section 20A isformed as illustrated in FIG. 35.

Then, the common laminated section 20B is patterned by the REI, the ionmilling, or the like by using the resist R2 as the mask to form the bitline BL as illustrated in FIG. 36 and FIG. 37. Thus, the commonlaminated section 20B is made to also serve as the bit line BL.

Then, the protection film (the interlayer insulting film) 72 is formedso as to embed the connection layer 71 and the resistance change device20 as illustrated in FIG. 38. Thereafter, the protection film 72 may bepolished, for example, by the CMP to expose the connection layer 71 asillustrated in FIG. 39. Thus, the second member 70 in which theresistance change device 20 and the connection layer 71 are formed onthe second substrate 73 is formed.

Then, the second member 70 may be bonded to the back surface 60B of thefirst member 60 by using, for example, the substrate bonding techniquesuch as normal temperature bonding. The second substrate 73 may beeither left or removed by etching and so forth. As a result of theabove, formation of the semiconductor device 5 illustrated in FIG. 28 iscompleted.

Sixth Embodiment

FIG. 40 is a diagram illustrating a sectional configuration of asemiconductor device 6 according to a sixth embodiment of the presentdisclosure. In the sixth embodiment, the bit line BL is providedseparately from the common laminated section 20B of the resistancechange device 20. The semiconductor device 6 has the same configuration,function, and effects as the semiconductor device 5 of the fifthembodiment except for the above-mentioned point. Therefore, descriptionwill be made by assigning the same numerals to the correspondingconstitutional elements.

The semiconductor device 6 may be manufactured, for example, in thefollowing manner.

FIG. 41 to FIG. 48 are diagrams illustrating a method of manufacturingthe semiconductor device 6 in order of processes. It is to be noted thatwith respect to the processes that are the same as those in the fifthembodiment, description will be made with reference to FIG. 31.

First, the first member 60 is formed by the process illustrated in FIG.31 in the same way as in the first and fifth embodiments.

Then, after the bit line BL is formed on the second substrate 73, theresistance change device material film 29 and the connection layermaterial film 71A are formed on the entire surface on which the bit lineBL has been formed as illustrated in FIG. 41. As the resistance changedevice material film 29, the buffer layer material film 26A, theperpendicular magnetization layer material film 27A, the reference layermaterial film 23A, the tunnel barrier layer material film 22A, therecord layer material film 21A, and the cap layer material film 24A areformed in this order starting from the side close to the secondsubstrate 73 as illustrated with the enlarged size in FIG. 41.

Then, the resist R1 is formed on the connection layer material film 71Aas illustrated in FIG. 42.

Thereafter, the connection layer material film 71A and the resistancechange device material film 29 are patterned by the RIE, the ionmilling, or the like by using the resist R1 as the mask, to form theconnection layer 71 and the plurality of resistance change devices 20.The discrete laminated section 20A that includes the record layer 21 andthe common laminated section 20B that includes the tunnel barrier layer22 and the reference layer 23 are provided for the plurality ofresistance change devices 20. The discrete laminated section 20A and theconnection layer 71 are respectively separated into parts for each ofthe plurality of resistance change devices 20. The plane of the discretelaminated section 20A is formed into the circular shape or the shapesimilar to the circular shape as illustrated in FIG. 29. The commonlaminated section 20B is continuously provided across the plurality ofresistance change devices 20.

Then, an insulating film SWA that covers the resistance change device 20and the connection layer 71 is formed as illustrated in FIG. 44.

Then, etch-back is performed by the RIE and so forth by using theinsulating film SWA as the mask to form a side wall SW on a side surfaceof the discrete laminated section 20A and to separate the commonlaminated section 20B into parts for each of the resistance changedevices 20 as illustrated in FIG. 45 and FIG. 46. In the sixthembodiment, formation of the resistance change device 20 byself-alignment becomes possible by forming the side wall SW on the sidesurface of the discrete laminated section 20B, thereby attaining processreduction, improving alignment accuracy, and improving the reliabilityand degree of integration of the resistance change device 20.

Then, the protection film (the interlayer insulting film) 72 is formedso as to embed the connection layer 71 and the resistance change device20 as illustrated in FIG. 47. Thereafter, the protection film 72 may bepolished by, for example, the CMP to expose the connection layer 71 asillustrated in FIG. 48. Thus, the second member 70 in which theresistance change device 20 and the connection layer 71 are formed onthe second substrate 73 is formed.

Then, the second member 70 may be bonded to the back surface 60B of thefirst member 60 by using, for example, the substrate bonding techniquesuch as normal temperature bonding. The second substrate 73 may beeither left or removed by etching and so forth. As a result of theabove, formation of the semiconductor device 6 illustrated in FIG. 40 iscompleted.

It is to be noted that the manufacturing method of the sixth embodimentis not limitedly applied to the perpendicular magnetization type devicedescribed in the fifth embodiment. This manufacturing method may be alsoapplied to a case where the bit line BL is provided separately from thecommon laminated section 20B of the in-plane magnetization typeresistance change device 20, for example, as described in the thirdembodiment.

Seventh Embodiment

FIG. 49 is a diagram illustrating a sectional configuration of asemiconductor device 7 according to a seventh embodiment of the presentdisclosure. In the seventh embodiment, the ReRAM is included as aresistance change device 120. The semiconductor device 7 has the sameconfiguration, function, and effects as the semiconductor device 1 ofthe first embodiment except for the above-mentioned point and it ispossible to manufacture the semiconductor device 7 in the same way asthe semiconductor device 1 of the first embodiment. Therefore,description will be made by assigning the same numerals to thecorresponding constitutional elements.

The resistance change device 120 is configured of a laminated film thatincludes a first electrode 121, a resistance change layer 122 made of anoxygen deficient type oxide of transition metal, and a second electrode123. The first electrode 121 also serves as the bit line BL. The secondelectrode 123 is disposed in contact with the connection layer 71 and isconnected to the selection transistor 30 via the connection layer 71.The resistance change layer 122 is disposed between the first electrode121 and the second electrode 123.

The resistance change layer 122 is configured of a single layer film ofthe oxygen deficient type oxide film made of transition metals such asoxygen deficient type tantalum oxides and hafnium oxides or a laminatedfilm formed of a combination of the above-mentioned films.

Examples of the constitutional materials of the first electrode 121 andthe second electrode 123 may include Pt, Ir, Pd, Ag, and Cu as theelectrode materials that are liable to induce resistance change. On theother hand, examples of the constitutional materials of the firstelectrode 121 and the second electrode 123 may include metals such as W,Ni, Ta, Ti, and Al and metal nitride films of TaN and so forth as theelectrode materials that have difficulty in inducing the resistancechange.

There exists a desirable combination of the above-mentioned electrodematerials depending on the type of the selection transistor 30 to whichthe resistance change layer 122 is to be connected. For example, when anNMOS transistor is to be used, the material of the second electrode 123may be selected from electrode materials with which the second electrode123 has difficulty in inducing the resistance change and the material ofthe first electrode 121 may be selected from electrode materials withwhich the first electrode 121 is liable to induce the resistance change.On the other hand, when a PMOS transistor is to be used, the material ofthe second electrode 123 is selected from the electrode materials withwhich the second electrode 123 is liable to induce the resistance changeand the material of the first electrode 121 is selected from theelectrode materials with which the first electrode 121 has difficulty ininducing the resistance change.

A buffer layer (not illustrated) may be disposed between the firstelectrode 121 and the second substrate 73. In the above-mentioned case,the buffer layer is configured of a single layer or a laminated film ofCu, Ti, W, TiN, and so forth.

In the semiconductor device 7, when a voltage is applied from a notillustrated power source (a pulse application section) via the firstelectrode 121 and the second electrode 123, the resistance change layer122 is changed from a high-resistance state to a low-resistance state(or from the low-resistance state to the high-resistance state). Itbecomes possible to repeatedly perform information writing into theresistance change device 120 and deletion of the information writteninto the resistance change device 120 by repeatedly performing such aprocess.

Eighth Embodiment

FIG. 50 is a diagram illustrating a sectional configuration of asemiconductor device 8 according to an eighth embodiment of the presentdisclosure. In the eighth embodiment, a laminated structure of an ionsource layer and a resistance change layer is included as a resistancechange device 220. The semiconductor device 8 has the sameconfiguration, function and effect as the semiconductor device 1 of theabove-mentioned first embodiment except for the above-mentioned point,and it is possible to manufacture the semiconductor device 8 in the sameway as the semiconductor device 1 of the first embodiment. Therefore,description will be made by assigning the same numerals to thecorresponding constitutional elements.

The resistance change device 220 is configured of a laminated film thatincludes a first electrode 221, a memory layer 222, and a secondelectrode 223 as illustrated with the enlarged size in FIG. 50. Thememory layer 222 includes an ion source layer 222A and a resistancechange layer 222B in this order starting from a side close to the firstelectrode 221.

The first electrode 221 and the second electrode 223 are made of Pt, W,WN, Cu, and so forth.

The resistance change layer 222B is made of a metal oxide. Examples ofthe metal oxides include tantalum oxides, niobium oxides, aluminumoxides, nickel oxides, cobalt oxides, titanium oxides, hafnium oxides,zirconium oxides, gadolinium oxides and so forth or mixed materials ofthe above-mentioned oxides.

The ion source layer 222A may contain one or more of Cu, Ag, and Zn asionizable metal elements, and one or more of chalcogenide elements ofTe, Se, and S. Examples of the ion source layer 222A may include CuTe,GeSbTe, CuGeTe, AgGeTe, AgTe, ZnTe, ZnGeTe, CuS, CuGeS, CuSe, CuGeSe,and so forth. Further, B or rare-metal elements or Si may be contained.In addition, the order of laminating the ion source layer 222A and theresistance change layer 222B may be reversed.

A buffer layer (not illustrated) may be disposed between the firstelectrode 221 and the second substrate 73. In that case, the bufferlayer is configured of a single layer or a laminated film of Cu, Ti, W,TiN, and so forth.

In the semiconductor device 8, when a voltage pulse or a current pulseis applied from the not illustrated power source (the pulse applicationsection) via the first electrode 221 and the second electrode 223,electric characteristics, for example, a resistance value of theresistance change layer 222B may be changed, and thus informationwriting, deletion, and reading-out may be performed.

Modification Example 1

FIG. 51 is a diagram illustrating an example of a sectionalconfiguration of a semiconductor device 7A according to a modificationexample 1. The present modification example relates to the seventhembodiment that includes the resistance change device 120 configured ofthe ReRAM or the eighth embodiment that includes the resistance changedevice 220 having the laminated film of the ion source layer 222A andthe resistance change layer 222B. In the semiconductor device 7A, theresistance change device 120 (or the resistance change device 220) isdisposed in both of the second member 70 and the first member 60 so asto share the selection transistor 30 between these members in order toimprove the degree of integration.

Modification Example 2

It is to be noted that it is also possible to arrange the logic devicesection 1B on the front surface 61A side of the first substrate 61 andthe memory device section 1A that includes the selection transistor 30and the resistance change device 120 on the back surface 61B side of thefirst substrate 61 as with a semiconductor device 7B illustrated in FIG.52. Also in the above-mentioned case, it becomes possible to improve thedegree of integration. It is to be noted that an interlayer insulatingfilm 62A is disposed on the front surface 61A side of the firstsubstrate 61 and an interlayer insulating film 62B is disposed on theback surface 61B side of the first substrate 61.

The semiconductor device 7B of the present modification example may beformed by utilizing the front surface 61A side and the back surface 61Bside of one first substrate 61 as illustrated in FIG. 52 or may beproduced by substrate bonding in the same way as the semiconductordevice 4 of the fourth embodiment (see FIG. 27). In that case, thebonding surface 82 serves as a surface along which the substrateprovided with the transistor 30 and the substrate provided with thetransistor 40 are bonded together.

Although the present disclosure has been described by giving theabove-mentioned embodiments, the present disclosure is not limited tothe above-mentioned embodiments and may be modified in a variety ofways.

For example, in the above-mentioned embodiments, description has beenmade on the semiconductor devices that respectively include theresistance change device 20 configured of the in-plane magnetizationtype or perpendicular magnetization type STT-MTJ, the resistance changedevice 120 configured of the ReRAM, and the resistance change device 220having the laminated structure of the ion source layer 222A and theresistance change layer 222B. However, there is no particular limitationon the configuration of the resistance change device as long as it isthe memory device that includes two terminals (electrodes) and storesinformation in response to a change in resistance state and theresistance change device may have another configuration.

In addition, although description has been made, for example, byspecifically giving the configurations of the resistance change device20 and the selection transistor 30 in the above-mentioned embodiments,it may not necessary to include all of the constitutional elements andother constitutional elements may be further included.

Further, for example, there may be no limitations on the material,thickness and forming method of each of the constitutional elementsdescribed in the above-mentioned embodiments, and each constitutionalelement may be made of another material, may have another thickness, andmay be formed by another forming method.

It is to be noted that the technology may be configured as follows.

(1) A semiconductor device, including:

a first member including a selection transistor on a front surface sideof a first substrate; and

a second member including a resistance change device and a connectionlayer that comes in contact with the resistance change device, theconnection layer being bonded to a back surface of the first member.

(2) The semiconductor device according to (1), wherein

the resistance change device is a spin injection magnetization reversaltype memory device that includes a record layer, a tunnel barrier layer,and a reference layer in this order starting from a side close to theconnection layer.

(3) The semiconductor device according to (2), wherein

the second member includes a plurality of the resistance change devices,and

the plurality of resistance change devices include

a discrete laminated section that includes the record layer and isseparated into parts for each of the plurality of resistance changedevices, and

a common laminated section that includes the tunnel barrier layer andthe reference layer, and is common to the plurality of resistance changedevices.

(4) The semiconductor device according to (3), wherein

the common laminated section also serves as a wiring that is common tothe plurality of resistance change devices.

(5) The semiconductor device according to (3) or (4), wherein

the connection layer is separated into parts for each of the pluralityof resistance change devices together with the discrete laminatedsection.

(6) The semiconductor device according to any one of (2) to (5), wherein

the record layer and the reference layer are each configured of a film,an axis of easy magnetization of which is directed in a verticaldirection relative to a film surface.

(7) The semiconductor device according to any one of (1) to (6), wherein

the first member includes a back surface contact electrode between theselection transistor and the connection layer, the back surface contactelectrode penetrating through the first substrate.

(8) The semiconductor device according to any one of (1) to (7), furtherincluding:

a transistor of a peripheral circuit, wherein

the transistor of the peripheral circuit is disposed on a front surfaceside of the first substrate in the first member.

(9) The semiconductor device according to any one of (1) to (7), furtherincluding:

a third member including a transistor of a peripheral circuit on a frontsurface aside of a third substrate, wherein

a back surface of the third member is bonded to a front surface of thefirst member.

(10) A method of manufacturing a semiconductor device, including:

forming a second member that includes a resistance change device and aconnection layer that comes in contact with the resistance changedevice; and

bonding the connection layer to a back surface of a first member thatincludes a selection transistor on a front surface side of a firstsubstrate.

(11) The method according to (10), wherein

in forming the second member, a spin injection magnetization reversaltype memory device is formed as the resistance change device, the spininjection magnetization reversal type memory device including a recordlayer, a tunnel barrier layer, and a reference layer in this orderstarting from a side close to the connection layer.

(12) The method according to (11), wherein

in forming the second member, a plurality of the resistance changedevices are formed, and

as the plurality of resistance change devices,

a discrete laminated section and a common laminated section are formed,

the discrete laminated section including the record layer and beingseparated into parts for each of the plurality of resistance changedevices, and

the common laminated section including the tunnel barrier layer and thereference layer and being common to the plurality of resistance changedevices.

(13) The method according to (12), wherein

the common laminated section is made to also serve as a wiring that iscommon among the plurality of the resistance change devices.

(14) The method according to (13), wherein

the connection layer is formed by separating into parts for each of theplurality of resistance change devices together with the discretelaminated section.

(15) The method according to any one of (11) to (14), wherein

the record layer and the reference layer are each configured of a film,an axis of easy magnetization of which is directed in a verticaldirection relative to film surfaces.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. A semiconductor device, comprising: a firstmember including a selection transistor on a front surface side of afirst substrate; and a second member including a resistance changedevice and a connection layer that comes in contact with the resistancechange device, the connection layer being bonded to a back surface ofthe first member.
 2. The semiconductor device according to claim 1,wherein the resistance change device is a spin injection magnetizationreversal type memory device that includes a record layer, a tunnelbarrier layer, and a reference layer in this order starting from a sideclose to the connection layer.
 3. The semiconductor device according toclaim 2, wherein the second member includes a plurality of theresistance change devices, and the plurality of resistance changedevices include a discrete laminated section that includes the recordlayer and is separated into parts for each of the plurality ofresistance change devices, and a common laminated section that includesthe tunnel barrier layer and the reference layer, and is common to theplurality of resistance change devices.
 4. The semiconductor deviceaccording to claim 3, wherein the common laminated section also servesas a wiring that is common to the plurality of resistance changedevices.
 5. The semiconductor device according to claim 3, wherein theconnection layer is separated into parts for each of the plurality ofresistance change devices together with the discrete laminated section.6. The semiconductor device according to claim 2, wherein the recordlayer and the reference layer are each configured of a film, an axis ofeasy magnetization of which is directed in a vertical direction relativeto a film surface.
 7. The semiconductor device according to claim 1,wherein the first member includes a back surface contact electrodebetween the selection transistor and the connection layer, the backsurface contact electrode penetrating through the first substrate. 8.The semiconductor device according to claim 1, further comprising: atransistor of a peripheral circuit, wherein the transistor of theperipheral circuit is disposed on a front surface side of the firstsubstrate in the first member.
 9. The semiconductor device according toclaim 1, further comprising: a third member including a transistor of aperipheral circuit on a front surface aside of a third substrate,wherein a back surface of the third member is bonded to a front surfaceof the first member.
 10. A method of manufacturing a semiconductordevice, comprising: forming a second member that includes a resistancechange device and a connection layer that comes in contact with theresistance change device; and bonding the connection layer to a backsurface of a first member that includes a selection transistor on afront surface side of a first substrate.
 11. The method according toclaim 10, wherein in forming the second member, a spin injectionmagnetization reversal type memory device is formed as the resistancechange device, the spin injection magnetization reversal type memorydevice including a record layer, a tunnel barrier layer, and a referencelayer in this order starting from a side close to the connection layer.12. The method according to claim 11, wherein in forming the secondmember, a plurality of the resistance change devices are formed, and asthe plurality of resistance change devices, a discrete laminated sectionand a common laminated section are formed, the discrete laminatedsection including the record layer and being separated into parts foreach of the plurality of resistance change devices, and the commonlaminated section including the tunnel barrier layer and the referencelayer and being common to the plurality of resistance change devices.13. The method according to claim 12, wherein the common laminatedsection is made to also serve as a wiring that is common among theplurality of the resistance change devices.
 14. The method according toclaim 13, wherein the connection layer is formed by separating intoparts for each of the plurality of resistance change devices togetherwith the discrete laminated section.
 15. The method according to claim11, wherein the record layer and the reference layer are each configuredof a film, an axis of easy magnetization of which is directed in avertical direction relative to film surfaces.